1. Field
The present disclosure relates to a control device for an internal combustion engine.
2. Description of the Related Art
Known control devices for internal combustion engines include a control device described in Japanese Patent No. 4930634. The control device is designed to control the ignition timing, and in an example of which shown in FIG. 5, the ignition timing is controlled by the following control algorithm. First, torque efficiency is calculated by dividing the required torque by an estimated torque calculated based on the opening of the throttle valve and the torque efficiency is converted to air quantity efficiency KL. By searching a map with reference to the efficiency KL, a feedforward control term for the amount of delay at 50% burn point is calculated.
In addition, based on detection signals from an in-cylinder pressure sensor, the torque that is actually being generated by the internal combustion engine (hereinafter referred to as “generated torque”) is calculated, and a feedback control term is calculated by a PID control algorithm so that the deviation between the required torque and the generated torque converges to 0. Then, the amount of delay at 50% burn point is calculated by adding the feedback control term to the feedforward control term, the ignition timing is calculated by searching a map in accordance with the amount of delay and the number of revolutions of the engine NE, and the internal combustion engine is controlled so that it is actually ignited at the calculated timing.